Difference between revisions of "NAT Linux"

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== Linux IP Tables ==
+
= Linux IP Tables =
 
IP Tables is used for packet filtering and NAT/PAT translation on several Linux distributions including
 
IP Tables is used for packet filtering and NAT/PAT translation on several Linux distributions including
 
*Ubunto
 
*Ubunto
 
*Redhat
 
*Redhat
 
*Centos
 
*Centos
 +
== Basic NAT using IP Tables ==
 +
In the example below the internal network 192.168.1.0/24 is Source Natted (SNAT) to the external IP Address 83.90.47.30. Source nat also makes port translations. So the example uses NAT/PAT, and would be sufficient as a NAT/PAT solution for a private network.
 +
<pre>
 +
iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -d 0.0.0.0/0 -j SNAT --to 83.90.47.30
 +
</pre>
 +
use the command ''iptables -L -t nat'' to see the rule in the IPTABLES chains.
 +
<pre>
 +
[root@bkshost etc]# iptables -L -t nat
 +
Chain PREROUTING (policy ACCEPT)
 +
target    prot opt source              destination
 +
 +
Chain POSTROUTING (policy ACCEPT)
 +
target    prot opt source              destination
 +
SNAT      all  --  192.168.1.0/24        anywhere          to:83.90.47.30
 +
 +
Chain OUTPUT (policy ACCEPT)
 +
target    prot opt source              destination
 +
</pre>
 
[[Category:Linux]]
 
[[Category:Linux]]

Revision as of 11:30, 7 March 2009

Linux IP Tables

IP Tables is used for packet filtering and NAT/PAT translation on several Linux distributions including

  • Ubunto
  • Redhat
  • Centos

Basic NAT using IP Tables

In the example below the internal network 192.168.1.0/24 is Source Natted (SNAT) to the external IP Address 83.90.47.30. Source nat also makes port translations. So the example uses NAT/PAT, and would be sufficient as a NAT/PAT solution for a private network.

iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -d 0.0.0.0/0 -j SNAT --to 83.90.47.30

use the command iptables -L -t nat to see the rule in the IPTABLES chains.

[root@bkshost etc]# iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination
SNAT       all  --  192.168.1.0/24        anywhere           to:83.90.47.30

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination